Method and apparatus for balancing an electrostatic force produced by an electrostatic chuck
US5764471A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 8, 1996 |
| Grant date | Jun 9, 1998 |
| Priority date | — |
| Expiry date | May 8, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T279/23
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electrostatic chuck containing apparatus, and a concomitant method, for balancing the electrostatic force that the chuck imparts upon a workpiece. More specifically, the electrostatic chuck contains a chuck body having a pair of coplanar electrodes embedded therein and a wafer spacing mask containing a plurality of conductive support members deposited upon a support surface of the chuck body. The support members maintain a wafer, or other workpiece, in a spaced-part relation with respect to the support surface of the chuck body. Each electrode within the chuck is respectively connected to a terminal dual voltage power supply having a center tap. The center tap of the power supply is connected to the wafer spacing mask. As such, variations in the distance between the wafer and the electrodes due to variations in dielectric thickness, wafer backside roughness, chuck surface roughness, chuck surface conductivity or other physical variations that may cause changes in the electrostatic force are balanced by having the spacing mask connected to the center tap of the power supply.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.